Field of the Invention
The invention relates to a power relay for a vehicle, in particular for a commercial vehicle. A power relay of this type is disclosed by way of example in DE 10 2010 018 738 A1, corresponding to U.S. patent publication No. 2011/02671587.
Power relays of the generic type are used in vehicle technology, in particular in the case of commercial vehicles. The power relays are used in order to electrically separate the vehicle battery from the vehicle electrical network. In addition, relays of this type are used in order to connect electrical motors of adjusting apparatus, for example a hydraulic pump or a lifting platform. It is necessary for a power relay of this type in the case of a low voltage of typically 12 volts to 24 volts to be able to connect currents up to a current strength of approximately 300 amps and therefore it is necessary to construct the power relay in an accordingly solid manner. Conventional relays that are used for this purpose are generally embodied from a pot-shaped metal body (for example iron or steel) and a magnetic coil and a magnetic yoke and also a magnetic armature that is connected to a contact bridge using a double contact are arranged in the metal body.
The power relay conventionally contains solid connecting bolts (threaded bolts) that are embodied from metal, the bolts typically containing a diameter of 0.5 cm to 1 cm so as to connect the power relay to a load current circuit that is to be connected in the vehicle. Cable lugs of the connecting lines of the load current circuit that is to be connected are fixed in accordance with their intended use in an electrically contacting manner to these connecting bolts by screw nuts (contact nuts).
In the installed state of the relay, in particular in a vehicle, by way of example in a truck, vibrations that are caused by operating the truck and are transferred to the power relay are practically unavoidable. This can lead to an undesired increase in the transition resistance between the moving contact bridge and the connecting bolts that are fixed to the housing. This problem could indeed be countered by increasing the contact pressure. However, this would require a stronger magnet system, which is not desirable.